Rolling motion generating gearing for grinding machines and testing apparatus for bevel wheels



June 11, 1946. A. ,AEPPLI ROLLING MOTION GENERATING GEARING FOR GRINDINGMACHINES AND TESTING APPARATUS FOR' BEVEL WHEELS Filed Dec. 6, 1943 sSheets-Sheet 1 vJume 11, 1946. AEPPL; 2,401,$1@

ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTINGAPPARATUS FOR BEVEL WHEELS Filed Dec. 6, 1943 5 Sheets-Sheet 2 v 2 2A 25Q a 26 June 11, 1946. A. AEPPLI 2,401,810

ROLLING MOTION GENERATING GEARING FOR GRINDING MACHINES AND TESTINGAPPARATUS ,FOR BEVEL WHEELS Filed Dec. 6, 1943 3 Sheets-Sheet 3fzz'merziorr Patented June 11, 1946 ROLLING MOTION GENERATING GEARINGFOR GRINDING MACHINES AND TESTING APPARATUS FOR BEVEL WHEELS AlbertAeppli, Zurich, Switzerland, assignor to Maag-Zahurader und-MaschinenAktiengesellschaft, Zurich, Switzerland Application December 6, 1943,Serial No. 513,105 In Germany July 4, 1942 4 Claims. 1

This invention relates to rolling motion generating gearings forgrinding machines and testing apparatus for bevel Wheels.

For rolling motion generating gearings for machine tools for machininggear wheels, more particularly gearings of this kind intended for use inconnection with testing apparatus, extremely high precision of operationis required.

This can be expected only if the working parts thereof are manufacturedwith utmost accuracy, said parts are few in number and the connectionsbetween them are of high grade efficacy.

The rolling motion generating gearing accord ing to the presentinvention is characterized in that in it the two rotational movements ofwhich the rolling motion of a cone can be composed, that is, therotational movement about the axis passing through the apex of the coneof the imaginary plane wheel and that about the axis of the cone areconverted in such manner that said rotational movements are no longerperformed about intersecting but about parallel axes by which means saidmovements can be combined with each other in simplest manner at shortestaxle spacings with the aid of known means so as to realise theobtainment of a relation between both rotational movements resulting inthe form of a ratio of diameters of cylindrical transmission members.

Several embodiments of the present invention are illustrated, by way ofexample only, in the accompanying drawings in which Fig. 1 shows aschematic elevation of the working parts of the rolling motiongenerating gearing according to the invention;

Fig. 2 is a corresponding top plan View;

Fig. 3 shows a side elevation;

Fig. 4 shows an elevation of a modified embodiment of the gearing;

Fig. 5 is a side elevation of Fig. 4;

Fig. 6 shows an elevation of a third embodiment of the invention;

Fig. 7 is a view of a modified detail of Fig. 1;

Fig. 8 is a top plan view corresponding to Fig. 7;

Fig. 9 shows an elevation of the gearing schematically illustrated inFig. 1;

Fig. 10 is a top plan view corresponding to Fig. 9, and

Fig. 11 is a side elevation corresponding to Fig. 9.

In the drawings numeral I indicates the work piece of which a bevel gearis to be formed shown in working position in the machine.

Referring to Fig. 9, a bed carries a vertical pin 2| and serves as amounting for a turntable 22 which is guided by said pin and anintervening ball bearing, the table 22 being integral with a standard 8.In two vertical relatively opposed walls of this standard eye bearings23 are arranged the common axis of which intersects the extended axis ofpin 2| at right angles thereto. In these eye bearings are mounted thearms 24 of a swing 9 in which a work spindle 25 is mounted. The extendedaxis of this spindle intersects that of the eye bearings 23perpendicularly as well as the extended axis of the pin 2|. The swing 9can be inclinedly adjusted to the axis of the pin 2|. To this end theswing is provided with laterally extending studs 26 which projectthrough arcuate slots 2'! in the walls of the standard 8 and carryclamping nuts 28.

On the turntable 22 a Worm wheel segment 29 is fastened into whichmeshes a worm 30 mounted in the bed 20. This worm is rotated in oppositedirections by means of a gearing not posably roll if it is to be groundon the rolling motion principle. The two axes x and y intersect eachother at the cone apex S (Fig. 1). With the spindle 25 a rollingcylinder 2 is firmly connected which in turn is coupled through tapes 3,4 with a cylinder 6 mounted on a countershaft 5 (Fig. 2). The shaft 5 ismounted in the swing 9 so as to extend horizontally underneath thespindle 25 and crossing it'at an angle of The tapes 3 and 4 function inthe manner of a crossed belt drive.

Said tapes extend between the two cylinders 2 and 6 at right angles totheir axes and parallel with each other so as to couple these cylindersfor common rotation devoid of play. A rolling cylinder 1 is sustained bythe pin 2| with its axis yremaining stationary. On the standard 8 (Fig.9) is further rotatably arranged a horizontal counterdrive shaft ill(see also Fig. 1) on which a cylinder is mounted. This cylinder isconnected with a rolling cylinder 7 through tapes 3| in the fashion of acrossed belt drive. The tapes 3|,therefore, extend between the twocylinders I and H at right angles to the axes thereof and in parallelismwith each other.

The shafts and iii carry on their outer ends belt pulleys i3 and I2,respectively, about which a steel tape [4, 1-5 is passed. In order toprevent expansion of this steel tape as much as possible in therectilinear sections thereof strips 3| of greater strength are included.

During the swinging movement; of thetur-n table 22 the tapes l4, l5beingalternatelywound on and off the cylinder 1 impart rotative-move--ment to the cylinder I l which movement is transmitted by the tapes l4,l5 to the shaft 5'which in turn rotates the work spindle =25; The-ratioof the two rotational movements, that is, the one about the axis y tothat about theaaxis a:, which ratio should be equal to sin a (Fig. 1),mustibe' i equal to the relation between the cylinder diam! eters citesIn Figs; 4"and"5 "a modified form of 'the gearing is shown. Inthis'arrangement the shafts 5 and are mount'ed in the "same manner *asprecedingly described; They are; however, not coupledby steel tapessuch-as 4 and l51butby an arcuate sector; It 1 which. is swingablymounted coaxiall with'the eye bearings'23 andi -coupled to cylindricaldiscs" HZ; Il3-that are-secured-to=the' shafts bandIllrespectivelybyrrolling-tapes I M,

In Fig. 6 a further embodiment" of the invention is shown in which theswingable sector- Itshown in Fig; 4*is' replaced by-a bar-2| which isdisplace-able in its longitudinal direction and-e'to which rolling:bands -;l M; H 5 are "fastened.

In'Figs: 7 and'8 'parts'of another modificationare shown. In this"arrangement the spindle 2-5 carrying the 'work I andthe'shafti areso-mounted in the swing 9 as to lie in"a--common: plane passing throughthe axis of rotation of the swing. They are coupled to eachother forcornmonsrotation by a" rack lfr'which slides inthe swingfi-perpendicularl to this plane andmeshes in spur gears 11,- I8 whichare secured -tothe spindle 25 and the shaft :5'respectively.This-arrangement presents, in distinction from a possible mode of"coupling the two: shafts 5'an'd 25 by means of bevel wheels; theadvantage that the spur gear tooth systems used-c-an'be manufacturedmore'pr'eciselytotrueform: A-similar operative connection forthegearingbeing comthegrinding disc is retractedfrom'the tooth gap having beenma'chinedina known manner, the

relative rolling motion" is reversed and the rolling motion generatinggearing restored into initial position. During the restoring movement"the work is revolubly advanced for one tooth division, whereupon the"rolling movement is reversed into the working direction again and theworking tool is further applied to the work in which way a fresh workingoperation is initiated. The machine may also be constructed so as to beable to further machine the same-tooth flanks also duringthe-backwardrolling motion and divides only at the end of the cycle of rollingoperations or'divides on the completion of the traverse performed brolling forwardly and grinds the tooth flankof anothertooth gap whilerolling backwardly;

Eevel wheel grinding machines for which,

above all, extreme accuracy of the product is required are to beequipped with a rolling motion generating device as shown in Figs. 1-6and 9-11.

Those machines, however, can be equipped with a rolling1motiongenerating device as shown in Figs. '7 and 8 for which maximum possibleprecision is not required but instead an amount of production as greatas possible such as conventional inwhat may be termed-singb use -orspecial Working tools which serve only one purpose and in which onlya'few-sizes of Wheels are machined by quantity production and the gearteeth of the gearing are required to be ground into accurately trueform.

Bevel wheels of accurate'configuration produced in themannerhereinbefore described may be used=for making bevel wheel drives forsubstitution with connections between the axis wand the counterdriveshaft 5 on one hand'and bes I tween the axis y and theshaft ill on the'otl'ier. Theoretically an appropriate connection serving this purposemay also consist in ascrew wheel drive having crossed axles,Howeven'such drives scarcely enter into the question due toprematurewear on the gear teeth owing to point bearing engagement betweencooperating te'eth.

For testing apparatus only the tape-connection between cylinders asdescribed enters' into -the' For suchapparatus a testing feelerquestion.

member is substituted for the grinding disc.

The grinding "disc 32'indicated 'in Fig, 1 describes with its grindingedge aplane surface which coincides with the flank of an imaginary planewheel extending coaxially-wi-th the-axis 11 perform a rolling movement.

I claim:

1. In a rolling motion generating'mechanism for grinding and testingbevel gears. a first member mounted to rotate about-an axis, a secondmember supported on the first member and mounted to rotate about anotheraxis, which serves for holding the work, a pair, of counterdrive shaftsparallel to each other respectively mounted perpendicularly relativelyto the respective axes, rotary motion transmitting means conmeeting saidcountershafts, and rotary -motion transmitting means connecting therespective shafts with the respective members to whose axes they aremounted perpendicularly.

2. A rolling motion generating mechanism for grinding and testing bevelgears according. to claim 1, and a pair of cylinders respectivelymounted on said countershafts, thetransmitting means between said shaftscomprising, a'steel band operatively interconnecting said cylinders, anda pair of crossed bands opcrativel interconnecting said oylinclers andtheir respective'rotar members. I

3. A rolling motion generating mechanism for grinding and testing-bevelgears according to connecting the shafts with the respectivemem- On thisflank the'work l is supposed to bers comprise cylinders mounted on saidcountershafts, and crossed bands interconnecting the cylinders withtheir respective rotatable members, the rotary motion transmitting meansbetween the countershafts including a removable and replaceable ratiogearing.

4. A rolling motion generating mechanism for grinding and testing bevelgears according to claim 1, and in which the countershafts are providedwith cylinders mounted thereon, and crossed bands interconnecting thecylinders with the respective members to whose axes they are mountedperpendicularly, the rotary motion transmitting means connecting thecountershafts including speed ratio producing means for providing aspeed ratio equal to that existing between the said two rotatablemembers.

ALBERT AEPPLI.

